The present invention relates to providing navigation services to portable communications devices, such as cellular phones, pagers, PalmPilot.RTM.-type devices or other types of portable phone devices.
There are various different types of portable navigation systems that provide navigation-related features. One type of portable navigation system has a geographic database physically installed with the portable navigation system unit. This type of portable navigation system is sometimes installed in vehicles. Because this type of navigation system has its own geographic database, it is relatively autonomous, e.g., it can provide navigation-related features during normal operation without the need to obtain data or programs from an outside source. However, with this type of navigation system there is a need to install updated geographic data in the system from time-to-time. Also, the navigation features provided by this type of navigation system are limited to the data contained in the geographic database physically installed with the navigation system, i.e., it cannot be used to provide navigation-related services about geographic features that are not represented by the on-board geographic database.
Another type of navigation system does not use a geographic database installed locally with the navigation system unit. Instead, this type of navigation system uses a wireless communication link to access a remote geographic database. This type of navigation system does not require that updated geographic data be obtained from time-to-time for the in-vehicle navigation system because the remote geographic database can be updated as frequently as needed.
Another type of navigation system combines a local geographic database (i.e., one that is physically installed with the navigation system) and a remote database. The local database is used whenever possible but the remote database is used to obtain data which is not available locally. This type of navigation system is described in U.S. Pat. No. 5,542,789, the entire disclosure of which is incorporated by reference herein.
Each of the different types of navigation systems described above can be used with some kind of positioning system hardware component. The positioning system hardware component may implemented using any of various types of technology, such as GPS technology, dead reckoning technology (inertial sensors), or a combination of GPS and dead reckoning technology. The positioning system hardware component may be part of the navigation system or may be a standalone component. The positioning system hardware component determines where the navigation system is located. Using the information provided by the positioning system hardware component and data from a geographic database (wherever it is located), the navigation system can provide useful navigation-related features, such as determining a route from the current location of the navigation system to a desired destination or identifying all the businesses of a particular type close to the current location of the navigation system.
Although navigation systems, like those described above, provide many useful features, there is still a need for additional types of systems that can provide navigation services to users.